Rotary vane hydraulic motor



June 23, 1970 M. KORHONEN 3,516,769

ROTARY VANE HYDRAULIC MOTOR Filed Feb. 10, 1967 SheetsSheet 1 3 gm 3 N 0') o N u 0- 8 .0- 3 LL u 9 INVENTIOR MARTTI KORHONEN ATTORNEY J1me 1970 M. KORHONEN ROTARY VANE HYDRAULIC MOTOR 2 Shea ts-Sheet 3 Filed Feb. 10, 1967 mm 5 3E 8 SN 8 3 3 n a INVENTOR MARTTI KORHONEN ATTORNEY United States Patent 3,516,769 ROTARY VANE HYDRAULIC MOTOR Martti Korhonen, Tasavallankatu 28, Kuopio, Finland Filed Feb. 10, 1967, Ser. No. 615,096 Int. Cl. F01c 1/00, 3/00 US. Cl. 418175 ABSTRACT OF THE DISCLOSURE A rotary vane hydraulic motor comprising an annular rotor encircling a peripheral surface on a stator and defining therewith a plurality of chambers. A plurality of radial vanes slidably disposed in vane slots in the stator project outwardly to engage the rotor. Fluid supply passages in the stator supply operating fluid to one side of each projecting vane and fluid exhaust passages in the stator communicate with the opposite sides of the pro jecting vanes respectively. A rotary sleeve valve synchronized with relative movement of the stator and rotor communicates with the bottom of each vane slot through four passages, two of which are equipped With check valves, and provides for relative rotation of the stator and rotor in either direction while supplying fluid under pressure to the bottom of each vane slot during movement of the coacting vane through an individual chamber and serving to exhaust fluid from the bottom of the vane slot as the vane moves between adjacent chambers.

The invention concerns a hydraulic motor comprising 2 Claims a stator, a rotor, and a distributing device for conducting pressure fluid into work spaces or chambers for operating fluid between the stator and the rotor and away from the workspaces or chambers. Reciprocating slide members or vanes extend radially into the workspaces.

Mechanization of transports now in progress in agriculture and forestry and endeavours to improve the economy of transports have lead to an ever increasing need for more effective ground vehicles. The same need also appears in the defense forces. The problem has been to find a suitable system of transmitting power, for instance, to the tractor trailer in order to make the wheels of the trailer also draw under difficult ground conditions. The present hydraulic motor has turned out in principle to be suitable for the purpose. At this moment there are already some such hydraulic motors which can be connected, for instance, to the hubs of the trailer wheel. The working principle of these hydraulic motors resemble that of piston engines.

This invention deals with a hydraulic motor operating according to the rotor principle, i.e. the reciprocating motion of ordinary pistons is replaced by the rotational motion of a rotor, offering a design which is simpler, more reliable in operation, cheaper and of higher efficiency. The motor has a rotating part, the rotor, e.g. the outer periphery of the device, and the stator or the stationary part fixed to the shaft. In addition the motor has a distributor of pressure fluid, obtaining its motion from the rotor, by means of which pressure fluid is conducted to the workspaces of the motor and away therefrom.

The main characterizing feature of the invention is that the workspaces consist of recesses in the peripheral surface of the rotor running parallel with the shaft of the motor, the surface of the stator, and of slide members in the stator moving in corresponding holes, at which the motion of the slide members takes place with the aid of springs and/or pressure fluid controlled by the distributing device. On reaching the switching area between the workspaces the slide member is pressed into its hole. Either the peripheral part or the control part of the motor may serve as rotor depending on which one is allowed to rotate and which one is stationary. Pressure fluid may be conducted to the workspaces either through the shaft or the outer part of the motor.

The number of workspaces is chosen according to need. In order to avoid the formation of dead centers one may for instance arrange the workspaces or the slide members unsymmetrically relative to one another, i.e. if for instance the workspaces on the periphery are of equal size the number of slide members is chosen for instance one less or one more than the number of workspaces. Different types of slide constructions, valves, etc., known as such may be used as distributors of pressure fluid.

In the hydraulic motor it is important that the turning moment immediately after bringing pressure fluid into the motor reaches maximum valve also at zero number of revolutions, i.e. for instance in the case that the vehicle has stopped the wheels of the trailer provided with hydraulic motor are made to draw at full capacity. When the terrain permits a higher speed with the vehicles own drawing power, the hydraulic motor may be switched ofl from operation, i.e. it rotates on free. By switching the flowing direction of the pressure fluid the other way around the hydraulic motor will rotate in the opposite direction, for instance on backing the vehicle. The operation of the hydraulic motor requires an outside source of power, a hydraulic pump, the control valve of which permits regulation of the above-mentioned operations. Furthermore, by regulating the flow of pressure fluid by means of the control valve stepless regulation of the rpm. of the hydraulic motor is achieved. This hydraulic motor has many applications, for instance, as means for driving conveyors, or the feeding device of circular saws, or it can be used where stepless control of the speed of rotation is required.

The invention is clarified further below with the aid of the enclosed schematical drawings, presenting only one working example of the invention, in which:

FIG. 1 presents a longitudinal section of the hydraulic motor according to the invention, and

FIG. 2 presents a cross-section of FIG. 1 along the line lIII,

. FIG. 3 presents on a larger scale the slide member, including related parts partly visible,

FIG. 4 presents a longitudinal section of the rotary slide used as distributor of pressure fluid,

FIG. 5 presents different stages of operation of the rotary slide according to FIG. 4,

FIG. 6 presents the bores of the distributor of pressure fluid in motor shaft and stator, and

FIG. 7 presents the distributor bores in the rotary slide.

In the hydraulic motor according to the drawing the shaft does not rotate but only the outer periphery, and pressure fluid is conducted to the motor through the shaft.

In the drawing the symbols designate the following: 0 switching area, 1 rotor, 2 slide member or vane, 3 stator, 4 shaft, 5 rotary slide, 6 end Wall, 7 end wall, 8 bearing, 9 flange, 10 packing, 11 ring packing, 12 shaft nut, 13 one-way valve, 14 ring packing, 15 workspace, 16 pressure fluid inlet channel, 17 pressure fluid return channel, 18 waste fluid discharge channel, 19 pressure fluid inlet channel, 20 fluid discharge channel.

According to the drawing the stator 3 is fixed by means of wedges 21 to the stationary shaft 4 to which the circular rotor 1 is mounted by means of bearings 8 to rotate about the stator 3. The inner peripheral surface of the rotor 1 is provided at intervals in the axial direction with recesses 15, for instance the bottom of which are concentric with the rotor shaft, which recesses together with the 3 outer surface of the stator form the workspaces, in number in the case presented, between which the remaining radial inwardly directed outstanding parts serve as switch regions 0, the purpose of which is clarified further below.

The stator 3 is provided in the longitudinal direction with radially located slot-like holes or vane slot 22, of which there are one more than the number of workspaces in the case presented. These holes 22 reach from a distance off the inner surface of the stator 3 to the outer periphery of the stator. Each hole 22 has a plate-like slide member 2 inside, the length of which radially mainly corresponds to the depth of the hole 22. However, a spring or springs (not presented in the drawing) may be fitted between the bottom of the hole 22 and the inner end of the slide 2, which seek to push the slide outwards. In such a case the radial length of the slide member may be smaller than the depth of the hole 22. According to FIG. 2 a radial inlet channel 19 for pressure fluid goes through the stator 3 into each workspace 15, and continues radially also through the shaft 4, and likewise a similar discharge channel for pressure fluid a distance from the inlet channel 19. The last-mentioned channel is located in front of the slide 2 in the direction of rotation and the discharge channel 20 behind the slide, and in the axial direction at a distance from the discharge channel 20. In addition two radial channels 23, 24 lead behind the slide 2 in each hole 22 through the stator 3 and the shaft 4, the one channel 23 being provided with a one-way valve 13, and two radial discharge channels 26, the one channel 25 being likewise provided with a one-way valve 13, which permits fluid to flow only in the direction of the radius of the motor shaft 4 outwardly towards the hole 22, but not in the opposite direction.

To the end of the stationary shaft 4 provided with a bore a rotary slide 5 of a design known as such is mounted to serve as distributor of pressure fluid, the inner surface of which is provided with a ring shaped distribution space 27 for pressure fluid, and a likewise ring shaped discharge space 28 at a distance from the former space in the axial direction. An inlet channel 16 running along the longitudinal axis of the shaft conducts pressure fluid into the distribution space 27 by way of the radially extending transversal channels 29, and a discharge channel 17 is running through the shaft to the discharge space. In addition a longitudinal channel 18 conducts possible waste fluid through the shaft 4 from the bearings 8 of the rotor 1.

FIG. 6 shows from above the bores in the motor shaft and the stator situated partly at the bottom of the hole 22.

FIG. 7 shows likewise from above the bores in the rotary slide, of which same bores those bores are seen also in FIG. 6 which coincide with the bores in the stator and the shaft.

FIG. 4 and particularly FIG. 5 shows the relative positions of the bores in the rotary slide and the shaft. Namely, FIG. 5 shows the sections 01- of the FIGS. 5, 6 and 7 at the dotted lines a-f, seen in the direction of the arrows in FIG. 4.

From the distribution space 27 of the rotary slide 5 three bores 24a, 23a, 19a, extending to the outer periphery of the rotary slide, either coincide with the channels 24,'

23 of the shaft 4 and the stator 3 conducting into the hole 22 of the slide member, or are in the position shown in FIGS. 1, 4, 5, 6 and 7. Similarly three radial bores 25a, 26a, 20a lead from the discharge space 28 of the rotary slide 5 through the latter, which either coincide with the channels 25, 26 of the shaft 4 and the stator 3 conducting into the hole 22 of the slide member and the discharge channel 20, or are in the position shown in the FIGS. 1, 4, 5, 6 and 7. At the inlet and discharge openings 19a and 20a, and at the openings 23a and 25a provided with oneway valves, recesses which are oval in the direction of rotation are made in the peripheral surface of the rotary slide 5.

The hydraulic motor according to the invention operates in the following manner:

The pump not seen in the drawing pumps pressure fluid into the ring-shaped distribution space 27 of the rotary slide 5 through the inlet channel 16 and the cross channels 29 of the shaft 4, from where it is able to enter the bore 23a, the channel 23, and by way of the one-way valve the hole 22 behind the slide member 2, in order to push the slide member against the bottom of the workspace 15. A spring possibly provided in the hole 22 behind the slide member further grants the pushing of the slide member into the workspace and against its wall. At the same time as the hole 23a opens also the hole 19a in the rotary slide opens, at which pressure fluid flows from the distribution space 27 to the work space 15 along the inlet channel 19 to the front side of the slide member 2 relative to the direction of rotation, at which the rotor 1 strives to rotate rotating also the rotary slide 5. At the same time as the hole 23a and the channel 23 opens, also the hole 25:: of the discharge space opens. However, fluid is not able to flow this way, because the one-way valve 13 closes the channel. When the slide member 2 has reached the end portion of the work space 15, i.e. where the switching range 0 sets in, the hole 19a and the inlet channel 19 are closing, and likewise the hole 23a closes and the hole 26a opens to the channel 26, at which fluid is able to leave from behind the slide member 2, and the slide member is able to move further into its hole, while the outstanding part, or the switching range 0 moves past the slide memher, at which the hole 20a and the channel 20 have closed and a new working phase is setting in. As the rotary slide 5 opens and closes in the above manner the channels intended for the different slide members 2, even rotation of the rotor 1 is accomplished.

Namely, as the rotor revolves the rotary slide bores and the above-mentioned channels coincide in such a Way, that the channels formed each time conduct pressure fluid into the workspace in front of the slide member 2, and correspondingly fluid is able to discharge from the workspace behind said slide member, at the same time as the fluid pressure keeps the slide member pushing against the wall of the workspace.

When the slide member reaches the switching area 0 the inlet and discharge channels in front of and behind the corresponding slide member are closed, and likewise that channel through which incoming fluid pushes the slide member against the wall of the workspace.

By changing the direction of the flow of fluid in the motor the inlet channels serve as discharge channels compared to the above, and vice versa, at which the direction of rotation of the motor changes to the opposite as the dotted arrow in FIG. 2 indicates.

The device according to the invention offers namely the advantage that in the case of any leak of fluid between the slide member and the wall of the workspace, or between the switching area 0 and the stator wall, fluid is just discharging through the discharge channel from that part of the workspace into which pressure fluid is leaking.

Naturally, the invention is not restricted to the above presented working example only, but it can be varied considerably Within the scope of the invention as to details. Thus, for example, the rotor may also comprise a rotating central body inside of the'stator, at which the workspaces comprise recesses made in the outer peripheral surface of the rotor. Also in this case the slide members are fitted into the stator, while pressure fluid is conducted to the workspaces during the working phase, and away from here during the discharge phase, and if necessary into the holes of the glide members and away from here, but this conduction of pressure fluid is now taking place through the outer periphery of the motor.

What is claimed is:

1. A hydraulic motor comprising, in combination, a first element defining thereon a first annular surface facing radially outward, a second element encircling said first element and defining a second annular surface facing radially inward in confronting relation to said first annular surface, said first and second elements being rotatable in relation to each other, said second annular surface on said second element including chamber segments thereof of arcuate shape radially spaced from said first annular surface to define therebetween chambers for operating fluid and being successively spaced apart by intervening sealing segments of said second surface closely confronting said first surface to effectively seal off communication between adjacent chambers, members covering opposite ends of said respective chambers to define the ends thereof, said first element defining a plurality of circumferentially spaced radial vane slots opening radially toward said second annular surface, a plurality of vanes slidably disposed in said respective vane slots to project therefrom into sealing engagement with said second annular surface, means defining operating fluid supply passages communicating with said respective chambers and exhaust passages communicating with said respective chambers on opposite sides of vanes extending into the respective chambers, a rotary valve interconnected with said first and secondelements for operation in synchronism with relative rotation of said first and second elements, means defining two plenum spaces communicating with said vane control valve and being selectively communicatable respectively with vane control fiuid under pressure and with exhaust, said first element defining for each of said vane slots two vane control fluid supply passages communicating with the bottom of the vane slot inwardly of the vane therein and corresponding to said respective plenum space-s, each of said vane control fluid supply passages having a check valve therein oriented to pass fluid through the passage only in the fiow direction of the coacting vane slot, said first element defining for each of said vane slots two vane control exhaust passages communicating with the bottom of the slot inwardly of the vane therein and corresponding to said respective plenum spaces, said rotary valve defining therein control ports communicating with said plenum spaces and with said vane control fluid supply passages for each slot to connect both said plenum spaces with said vane control fluid supply passages for each vane slot to supply fluid under pressure to the bottom of the slot as the vane therein moves along each chamber segment of said second annular surface, and said rotary valve defining therein control ports communicating with said respective plenum spaces and coacting with said vane control exhaust passages for each slot to connect the bottom of the vane slot to the plenum space selectively connected to exhaust as the coacting vane moves from a chamber segment of said second annular surface onto an adjacent sealing segment of said second annular surface incident to rotation of said first and second elements relative to each other in a selected direction of rotation corresponding to the connection of a selected one of said plenum spaces to exhaust.

2. A hydraulic motor according to claim 1 in which fluid supply control ports in said rotary valve interposed between said respective plenum spaces and the two respective vane control fluid supply passages communicating with each vane slot have a substantial arcuate extent corresponding in radial angle to the radial angles of chamber segments of said second annular surface, and exhaust ports in the rotary valve intervening between said respective plenum spaces and the two respective exhaust passages communicating with the bottom of each slot have an arcuate extent which is decidedly less than that of said supply ports.

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